Correlation of next generation sequencing (NGS) of urine with tumor and plasma in patients with non-muscle invasive bladder cancer (NMIBC).

e16002 Background: The current standard-of-care surveillance protocols for post-treatment NMIBC patients involve invasive procedures that result in poor patient compliance. Detection of recurrent NMIBC tumor DNA in plasma or urine would provide a less invasive alternative, and here we examine the feasibility of this approach by performing targeted NGS on tumor, plasma, and urine samples from NMIBC patients. Methods: 5 patients with untreated NMIBC (histology: Ta(n = 3), T1(n = 2)) have been analyzed to date. Urine and plasma samples were taken just prior to tumor resection. Samples were analyzed using a capture panel that includes common mutations found in > 80% of NMIBC patients. Coverage includes the promoter region of the TERT gene, the entire coding regions of KDM6A and FGFR3, and copy number variation in PD-L1 and JAK2. Results: Mutations were observed in all tumor samples, with the TERT -124C > T promoter mutation found in 4 patients (AF:16-84%) and the TERT -146C > T promoter mutation found in the other (AF:19%). Deleterious mutations were found in KDM6A for 4 patients, and FGFR3 activating mutations were found in 2 patients. Amplification of FGFR3 was seen in one sample. When the 4 matched pairs of urine and tumor samples were examined, all of the called mutations in tumor were also found in urine at similar allele frequencies. This includes the detection of gene copy alterations. No such mutations were observed in plasma samples despite extensive sequencing ( > 2000 unique read coverage). Conclusions: These data show that canonical NMIBC mutations are readily detectable in urine and correlate well with tumor, suggesting that NMIBC tumors shed prolifically into urine, and indicate that further investigation of NGS sequencing of urine as a means of detecting NMIBC recurrence is warranted.